Panel type is one of the least important decisions in a solar project and one of the most heavily marketed. Orientation, shading, installation quality and system sizing all move output more than the choice between two reputable modules. What panel type does change is how much capacity fits in a given area, how the array looks, and occasionally what suits an unusual site.
Monocrystalline solar panels, polycrystalline and thin film
Monocrystalline cells are cut from a single silicon crystal and are the standard on British domestic roofs: highest efficiency per square metre, uniform dark appearance, and the reason a modern array needs fewer panels than an older one. Polycrystalline is made from cast multi crystal silicon, slightly less efficient per area, and now uncommon in new domestic installations. Thin film is lighter and more tolerant of heat and diffuse light but needs considerably more area for the same output, which is why it appears on large commercial roofs with weight limits rather than on houses.
New solar panel technology: bifacial panels and where they earn their keep
A bifacial panel generates from both faces, picking up light reflected onto its back. That is worth real output on a ground mounted array over a light surface, on a flat roof with a reflective membrane, or on an elevated frame. On a conventional pitched roof, where the back of the panel faces a tile a few centimetres away, the gain is close to nothing. It is a good technology sold in the wrong place more often than not.
Appearance: black frames, full black and coloured panels
All black modules with black frames and backsheets cost a little more and look considerably better on a dark roof, which matters on a prominent elevation and in a conservation area. Coloured panels exist and cost output as well as money, because the colour is achieved by reflecting the light they would otherwise convert. Where appearance is the constraint, solar slates and in roof systems usually do more for the look than a coloured panel does.
What efficiency figures tell you about different types of solar panels
Module efficiency is output per square metre under test conditions, so it tells you how much capacity fits in your area, not how well the array will perform. A higher efficiency panel is worth paying for when space is tight and is worth very little when the roof is bigger than the system you want. Compare quotes on kilowatts peak, modelled annual generation, warranty and degradation rate rather than on the headline efficiency of the module.
Questions people ask about types of solar panels
Which type of solar panel is best in the UK?
Monocrystalline for almost all domestic installations, because it fits the most capacity into a British roof area. The panel type matters far less than orientation, shading and installation quality, so it is not where a decision should turn.
Are bifacial panels worth it on a house?
Rarely on a conventional pitched roof, where there is nothing behind the panel to reflect light. They earn their cost on ground mounts, elevated frames and reflective flat roofs.
Do black solar panels perform worse?
All black modules run slightly warmer than silver framed equivalents, which costs a small amount of output. Most buyers who choose them are buying appearance and accept that trade, and it is a smaller effect than shading or orientation.
What does panel efficiency actually mean?
Output per square metre under standard test conditions. It determines how much capacity fits your roof area rather than how well the system performs, so it matters most when space is tight.
Are the new solar panels coming out worth waiting for?
Not usually. Bifacial, tandem and other laboratory advances arrive on roofs slowly, and the panel is not the part of a quote that decides whether the array pays: the scaffold, the labour, the inverter and the roof itself are. A system fitted now starts generating now, and the mounting and wiring will take a better panel in fifteen years if one is worth having.